The original photos of this model were found among a large pile of Lesney paperwork being disposed of (via rubbish skip) in London. The photos eventually came into the possession of Steve Brown who brought them to me at the same time as a number of his photo albums. While perusing the photos I noted this particular photo and asked if I could scan it as I thought I recognised the crest on the doors. Once scanned and magnified I was able to correctly identify the crest as the New Zealand Parliamentary Crest (aka the New Zealand Coat of Arms). It is not known why this particular crest was used on the doors of the pre-production model, but it is known that several New Zealanders worked in the Research and Development arm of the Lesney company at various times.
The Ministry for Culture and Heritage web site displays information on the history of the New Zealand Coat of Arms.